MPs have backed Prime Minister Boris Johnson's plan for the UK to leave the EU on 31 January.
They voted 358 to 234 - a majority of 124 - in favour of the EU (Withdrawal Agreement) Bill, which now goes on to further scrutiny in Parliament.
The bill would also ban an extension of the transition period - during which the UK is out of the EU but follows many of its rules - past 2020.
The PM said the country was now "one step closer to getting Brexit done".
Labour leader Jeremy Corbyn told his MPs to vote against the bill, saying there was "a better and fairer way" to leave the EU - but six of them backed the government.
Mr Johnson insists a trade deal with the EU can be in place by the end of the transition period, but critics say this timescale is unrealistic.
The bill had been expected to pass easily after the Conservatives won an 80-seat majority at last week's general election.
MPs also backed the timetable for further debate on the bill over three days when they return after the Christmas recess - on 7, 8 and 9 January.